The Effect of Packaging Covers and Gaseous Composition on Maintaining the Postharvest Quality of Marigold

Marigold (Calendula officinalis L.) is also known as one of the common edible flowers. In this study, the improvement of nutritional value and shelf life of marigolds under the covers of packaging and gaseous composition was investigated. Marigold flowers in plastic packages made of polyethylene, polyamide, and the combination of these two covers with gas composition (1: 5% O2 + 5% CO2; 2: 5% O2 + 10% CO2; 3: 5% O2 + 20% CO2) or without gas combination were placed along with the control (without packaging). These packages were transferred to the cold store at 4°C, and sampling was done to evaluate the desired traits on days 0, 5, 10, and 15. The results showed that with the increased storage time in all edible marigold flowers, the amount of weight loss, ion leakage, and decay increased, and the relative water content (RWC), total phenol, flavonoids, and carotenoids decreased. At the same time, using polyethylene and polyamide packaging treatment, along with gaseous composition, improved the visual and nutritional quality of flowers. Among all the treatments, the combination treatment of 5% O2 + 10% CO2 and polyethylene + polyamide coating had better effects in maintaining the quality and increasing the shelf life of the edible marigold flowers. As a result, considering the nutritional and medicinal value of the marigold flowers, this treatment can be used as an effective and safe method to increase the shelf life and maintain the appearance quality and biochemical compounds of this plant.